Cowling for airplanes



Oct. 1, 1946.. V D. M. CAPANOLI NOW BY JUDICIAL CHANGE OF NAME D. M. CAPPAN COWLING FOR AIRPLANES Filed Nov. 8, 1944 2 Sheets-Sheet I ouo-a oococ M. CAPANOL] I 2,408,371

NOW BY JUDICIAL CHANGE OF NAME D. M. CAPPAN COWLING FOR AIRPLANES Filed Nov." 8, 1944 2 Sheets-Sheet 2 l m o mull!!! g- 0 0 o o o o Patented Oct. 1, 1946 UNITED STATES PATENT OFFICE COWLING FOR AIRPLANES David M. Capanoli, now by judicial change of name David Marino Cappan, Hibbing, Minn.

Application November 8, 1944, Serial No. 562,475

1 Claim.

This invention appertains to improvements in a cowling structure for airplanes, and has for one of its several objects to provide an improved means for regulating the air flow through the cowl of an air-cooled airplane engine; said means functioning in a manner to effectively eliminate the drag on the airplane, and the resultant loss in the power of the engine, that is of common occurrence in the use of the radially adjustable flap, r louvre type of air flow control means, which is currently employed on certain makes of airplanes.

Another object of the invention has to do with the provision of a number of parallel tracks about the trailing edge of a ring cowling, the tracksextending axially rearwardly from the cowling edge and supporting longitudinally movable shutters, which normally close the air flow outlet space provided between the trailing edge of the engine cowling and the leading edge of the cockpit cowling, or the like edge of an accessory cowling if one be interposed between the engine cowling and the cockpit cowling, the movements of the shutters being controlled through a suitable mechanism from the instrument panel of the airplane. I With these and other objects and advantages in view, the invention resides in the certain new and useful combination, construction, and arrange of parts, as will be hereinafter more fully described, set forth in the appended claims, and illustrated in the accompanying drawings, in which:

Figure l is a side elevation of the nose of a Corsair type of airplane and showing the cowl structure and air flow regulating means, in accordance with the invention;

. Figure 2 is an enlarged, fragmentary, transverse section through the cowl structure and showing a portion of the interconnected operating mechanism for the shutters;

Figure 3 is an enlarged sectional detail, taken through the line 33 on Figure 2, looking in the direction of the arrows;

Figure 4 is a fragmentary, longitudinal section, taken through the line 44 on Figure 3, looking in the direction of the arrows;

Figure 5 is an enlarged fragmentary view of the cowl section.

- Figure 6 is a view of the transmission device used in actuating mechanism of the shutters.

Referring to the drawings, wherein like characters of reference denote corresponding parts in the several views, the invention, as it is exemplified therein, is comprised in a front annular cowling portion III, which is placed around the usual radial air-cooled engine (not shown) and is forwardly and downwardly curved to reduce the engine drag to a minimum, and a substantially cylindrical cowling portion l2, extending rearwardly from the annular portion to which it is secured by rivets or the like it. The cowling portion I2 is preferably made up of a plurality of rectangular metal panels l4, arranged in edge to edge abutting relation and, as best shown in Figure 5, these edges of each pair of adjacent panels are secured in that relation, by rivets or the like l8, to an underlying track structure.

Each track structure is comprised in a metal plate 26, disposed immediately beneath the abutted edge portions of adjacent cowling panels M, and a second metal plate 22 that is formed to provide a centrally disposed, longitudinally extending, inverted U-shaped portion 24, which has its cross correcting wall, together with the metal plate 20, secured to the cowling panels by the rivets i8. With this arrangement, portions 26, of the plate 22 at opposite sides of the U-shaped portion 24, are spaced from like portions of the plate 20, to form longitudinally extending channels therebetween. Secured to each of the opposed iaces of the spaced portions of the plates 250 and 22, by rivets or the like 28, is a strip of fiber or the like 30.

A shutter 32, of a selected gauge of sheet metal, is slidably supported in the opposed channels of adjacent pairs of the tracks and, to this end, has each of its longitudinal edge portions engaged between the opposed fiber strips 30, which prevent metal-to-metal contact and also air leakage about the edges of the shutters, when the latter are in air flow cutoff positions. As best shown in Figure 4, the rearwardly directed end of each shutter 3'2 is provided with an outwardly, acutely, angled portion 34, which acts not only to deflect the air stream about the cowling 12 away from otherwise possible ingress through the air flow outlet at the rear of the latter, but also tends to cause-a partial vacuum at the outlet that acts to accelerate the air flow through the cowling and its discharge rearwardly therefrom. Underlying each of the shutters 32, is a sheet metal plate 36, which is centered thereon between the edge portions engaged in the track channels, and has its rearwardly directed end bearing against and secured to the under side of the shutter, as by rivets or the like 40, and its forwardly directed end upwardly and forwardly angled, as at 38, with the forwardly angled portion secured thereto, by rivets or the like 42. The rearwardly directed end of the completed cowling I2 is spaced end edge portions 34 thereof overlie the forwardly directed end of the cowling A.

The shutters 32 are to be simultaneously operated to either open, or a partially open, and closed positions, through the medium of a suitable mechanism, e. g., a system of interconnected screw jacks, which are driven by a shaft 46 from a prime mover, such as an electric motor (not shown), that is to be controlled from a toggle switch or the like (not shown) on the instrument panel in the cockpit of the airplane. As shown in Figures 2 and 6, the shaft 46 is preferably in the form of a length of flexible shafting which leads from its connection with the shaft of the motor to a power transmission gear train, consisting of meshing gears 52, 54, and 56, that are enclosed within a housing 48, the latter being supported from an I-beam 50 that is made circular to conform to the interior circumference of the cowling I2. The annular beam 59 is located toward the front end of the cowl l2 and has a bracket 58 bolted, as at 60, to the rear side of its connecting web, to support one end of a jack assembly.

Each jack assembly is comprised in a pair of telescopic tubes 62 and Ill, the tube 62 opening into a gear casing 64, at its forwardly directed end, and the tube :0 terminating, at its rearwardly directed end, in an attaching eye 12, which is engaged on a pivot pin 14, carried in a bracket 15, that is secured on the under side of the reinforcing plate 36, of a shutter 32. The gear casing Ed carries an attaching eye 66, which is engaged on a pivot pin 58, that is carried in the bracket 58. threaded and. engaged by a screw threaded jack rod or shaft 18, which is keyed to a worm gear 88 and journalled in the walls of the casing 64, the worm gear being meshed with a worm 82, that is also journalled in the casing 64. The elements 82, of each of the jack assemblies, are interconnected by lengths of flexible shafting 84, except for those of the two jack assemblies nearest the opposite sides of the transmission housing 48, the worm elements of which are connected by shorter lengths of flexible shafting 86 to the gear 56, within the transmission housing; the gear 52, of the power transmission, being connected to the flexible shaft 46, leading from the prime mover.

From this description, it will be apparent to those skilled in aviation that, with the prime mover taking the form of a reversible motor and under the control of a reversing switch on the instrument panel of an airplane equipped with this improved cowl construction, the shutters 32 may be readily opened and closed, or partially so, at the will of the pilot, the jack tubes 10 being simultaneously retracted inwardly of the tubes 62, to move the shutters longitudinally of and toward the forward end of the cowl l2, in one di- The bore of the tube 10 is screw 4 rection of motor operation, and projected from the tubes 62 in a rearward direction to move the shutters to closed positions, in the reversed direction of motor operation. Also, it will be obvious that in the use of these longitudinally slidable shutters 32, there can be no drag effect on airplane travel by the same and, consequently, no undue bufieting of the airplane by air turbulence, or loss in power developed by the engine, such as occurs when the pivoted type of shutters, i. e., flaps, are employed. It is well known that aircraft engines are subject to high operating temperatures, particularly during engine check, takeoff, and climb, and these high temperatures can only be controlled by the use of shutters or flaps to regulate air flow over and about the engine, the regulation being governed by observations of the engine instruments for the best operation setting. Without reducing these high temperatures by such controls of the air flow through the cowls l0 and I2, detonation will set in and cause engine failure. Proper cooling of the engine cylinders depends not only upon the degree of opening of the shutters or flaps, but also upon the speed of the airplane, and it has been determined that, with the use of the instant longitudinally adjustable shutters 32, a greater nicety of regulation of the air flow is to be had, with a more economical fuel consumption and an increase in the power developed by the engine. In the known aircraft, employing the pivoted type of flap control for the air now over and about the engine, full opening of the flaps has been found to be very impractical, by reason of the drag caused by the pressure of the air stream, passing rearwardly over the outersides of the cowls l0 and i2, on the combined areas thereof and, without such opening, the cooling down of the engine is ineffective to prevent over-heating and engine failure;' whereas, the present slidable type of shutters can be fully opened, without any such results.

Having thus fully described my invention, it is to be understood that any and all changes in design, construction, and arrangement of parts thereof, may be resorted to, without departing from the scope of the appended claim.

I claim:

In combination with an engine, a front annular cowling encircling said engine, a substantially cylindrical cowling extending rearwardly in continuation of said front cowling, said cylindrical cowling being made up of a plurality of arcuate sections, a cockpit cowling rearwardly of and spaced from the rear end of the cylindrical cowling, oppositely channelled track elements underlying the adjacent side edges of said sections and secured thereto and extending across the space between the rear ends of the sections and the cockpit cowling, and arcuate shutters slidable in said track elements to close and open said space to regulate the air flow through said cowlings, said shutters being of sheet metal and each joined at its front edge to the adjacent portion of a plate clearing said track elements and also including a portion angularly spaced from the shutter and attached at its rear end to the shutter, and jack units each pivotally secured to the plate of a shutter and simultaneously operated.

DAVID M. CAPANOLI. 

